branch: externals/parser-generator
commit c0310bf426180199844413b67ec9c6624b59b1f1
Author: Christian Johansson <christ...@cvj.se>
Commit: Christian Johansson <christ...@cvj.se>
Added error-handling to lexical analyser
---
parser-generator-lex-analyzer.el | 89 +++++++++++++++++++-----------
test/parser-generator-lex-analyzer-test.el | 27 ++++++++-
2 files changed, 82 insertions(+), 34 deletions(-)
diff --git a/parser-generator-lex-analyzer.el b/parser-generator-lex-analyzer.el
index b9f30c3..6f0609f 100644
--- a/parser-generator-lex-analyzer.el
+++ b/parser-generator-lex-analyzer.el
@@ -15,11 +15,11 @@
(defvar parser-generator-lex-analyzer--get-function
nil
- "Get token information function.")
+ "Get token information function. This function will be called when building
token meta-information before calling optional syntax-directed translation /
semantic-actions. Anything other than nil is expected.")
(defvar parser-generator-lex-analyzer--function
nil
- "Function used as lex-analyzer.")
+ "Function used as lex-analyzer. This function will be called and as result
a list with structure '(a b . c) is expected where a is a string or symbol, if
no more tokens can be found nil is expected, if it's not possible to proceed
lex analysis an error-signal is expected.")
(defvar parser-generator-lex-analyzer--index
nil
@@ -33,14 +33,24 @@
;; Functions
-;; TODO Catch errors
(defun parser-generator-lex-analyzer--get-function (token)
"Get information about TOKEN."
(unless parser-generator-lex-analyzer--get-function
(error "Missing lex-analyzer get function!"))
- (funcall parser-generator-lex-analyzer--get-function token))
+ (let ((meta-information))
+ (condition-case error
+ (progn
+ (setq meta-information (funcall
+ parser-generator-lex-analyzer--get-function
+ token)))
+ (error (error
+ "Lex-analyze failed to get token meta-data of %s, error: %s"
+ token
+ (car (cdr error)))))
+ (unless meta-information
+ (error "Could not find any token meta-information for: %s" token))
+ meta-information))
-;; TODO Catch errors
(defun parser-generator-lex-analyzer--peek-next-look-ahead ()
"Peek next look-ahead number of tokens via lex-analyzer."
(unless parser-generator-lex-analyzer--index
@@ -52,41 +62,56 @@
(let ((look-ahead)
(look-ahead-length 0)
(index parser-generator-lex-analyzer--index))
- (while (< look-ahead-length parser-generator--look-ahead-number)
- (let ((next-look-ahead
- (funcall
- parser-generator-lex-analyzer--function
- index)))
- (if next-look-ahead
- (progn
- (unless (listp (car next-look-ahead))
- (setq next-look-ahead (list next-look-ahead)))
- (dolist (next-look-ahead-item next-look-ahead)
- (when (< look-ahead-length parser-generator--look-ahead-number)
- (push next-look-ahead-item look-ahead)
- (setq look-ahead-length (1+ look-ahead-length))
- (setq index (cdr (cdr next-look-ahead-item))))))
- (push (list parser-generator--e-identifier) look-ahead)
- (setq look-ahead-length (1+ look-ahead-length))
- (setq index (1+ index)))))
+ (while (<
+ look-ahead-length
+ parser-generator--look-ahead-number)
+ (condition-case error
+ (progn
+ (let ((next-look-ahead
+ (funcall
+ parser-generator-lex-analyzer--function
+ index)))
+ (if next-look-ahead
+ (progn
+ (unless (listp (car next-look-ahead))
+ (setq next-look-ahead (list next-look-ahead)))
+ (dolist (next-look-ahead-item next-look-ahead)
+ (when (<
+ look-ahead-length
+ parser-generator--look-ahead-number)
+ (push next-look-ahead-item look-ahead)
+ (setq look-ahead-length (1+ look-ahead-length))
+ (setq index (cdr (cdr next-look-ahead-item))))))
+ (push (list parser-generator--e-identifier) look-ahead)
+ (setq look-ahead-length (1+ look-ahead-length))
+ (setq index (1+ index)))))
+ (error (error
+ "Lex-analyze failed to peek next look-ahead at %s, error: %s"
+ index
+ (car (cdr error))))))
(nreverse look-ahead)))
-;; TODO Catch errors
(defun parser-generator-lex-analyzer--pop-token ()
"Pop next token via lex-analyzer."
(unless parser-generator-lex-analyzer--index
(error "Missing lex-analyzer index!"))
(unless parser-generator-lex-analyzer--function
(error "Missing lex-analyzer function!"))
- (let ((token (funcall
- parser-generator-lex-analyzer--function
- parser-generator-lex-analyzer--index)))
- (unless (listp (car token))
- (setq token (list token)))
- (let ((first-token (car token)))
- (setq parser-generator-lex-analyzer--index
- (cdr (cdr first-token)))
- first-token)))
+ (condition-case error
+ (progn
+ (let ((token (funcall
+ parser-generator-lex-analyzer--function
+ parser-generator-lex-analyzer--index)))
+ (unless (listp (car token))
+ (setq token (list token)))
+ (let ((first-token (car token)))
+ (setq parser-generator-lex-analyzer--index
+ (cdr (cdr first-token)))
+ first-token)))
+ (error (error
+ "Lex-analyze failed to pop token at %s, error: %s"
+ parser-generator-lex-analyzer--index
+ (car (cdr error))))))
(defun parser-generator-lex-analyzer--reset ()
"Reset lex-analyzer."
diff --git a/test/parser-generator-lex-analyzer-test.el
b/test/parser-generator-lex-analyzer-test.el
index 7666a57..e3fcc9c 100644
--- a/test/parser-generator-lex-analyzer-test.el
+++ b/test/parser-generator-lex-analyzer-test.el
@@ -26,11 +26,13 @@
(let* ((string '(("a" 1 . 2) ("b" 2 . 3) ("c" 3 . 4) ("d" 4 . 5)))
(string-length (length string))
(max-index index)
- (tokens))
+ (tokens)
+ (next-token))
(while (and
(< (1- index) string-length)
(< (1- index) max-index))
- (push (nth (1- index) string) tokens)
+ (setq next-token (nth (1- index) string))
+ (push next-token tokens)
(setq index (1+ index)))
(nreverse tokens))))
(should-error
@@ -59,6 +61,27 @@
'(("a" 1 . 2) ("b" 2 . 3) ("c" 3 . 4) ("d" 4 . 5) (e) (e) (e) (e) (e) (e))
(parser-generator-lex-analyzer--peek-next-look-ahead)))
+ (setq
+ parser-generator-lex-analyzer--function
+ (lambda (index)
+ (let* ((string '(("a" 1 . 2) ("b" 2 . 3) ("c" 3 . 4) ("d" 4 . 5)))
+ (string-length (length string))
+ (max-index index)
+ (tokens)
+ (next-token))
+ (while (and
+ (< (1- index) string-length)
+ (< (1- index) max-index))
+ (setq next-token (nth (1- index) string))
+ (when (string= (car next-token) "d")
+ (error "Invalid token: %s" next-token))
+ (push next-token tokens)
+ (setq index (1+ index)))
+ (nreverse tokens))))
+
+ (should-error
+ (parser-generator-lex-analyzer--peek-next-look-ahead))
+
(message "Ended tests for
(parser-generator-lex-analyzer--peek-next-look-ahead)"))
(defun parser-generator-lex-analyzer-test--pop-token ()
